1. Field of the Invention
The invention relates to a device for covering a surface that is easy to use and better meets the requirements of the application concerned.
2. Technical Background
Covers are applied to surfaces for reasons which are dependent on the nature of these surfaces.
Hence, in the case of a basin such as a swimming pool, the cover may prevent contamination by leaves or by animals, may save energy, water and reagents, and may or needs to ensure the safety of people, especially children. In a basin for the desalination or other treatment of a fluid, a cover prevents dilution of liquid due to rainwater or excessive evaporation due to heat.
In the case of a sports ground such as a clay court or grass court outdoor tennis court, a cover protects the court against inclement weather, particularly intermittent rain.
Furthermore, a vehicle body is covered particularly to ensure the stability of the load in the face of the suction caused by the movement of the vehicle and to protect this load against inclement weather.
Covers are also used as blinds for greenhouses, conservatories or vehicle windows to prevent any overheating inside, and as protection against the sun for patio awnings.
In all these scenarios, what is generally being sought is an economical cover device that allows covering and uncovering to be done easily, dependably, repeatably and quickly, with the need for a minimum amount of human intervention.
A very basic first device used in the case of a swimming pool comprises a cover which may or may not be inflatable which is unrolled, stretched out and fixed manually to the edges of the swimming pool. This type of device is illustrated for example in documents U.S. Pat. No. 6,691,334, GB 2 379 163 and FR 2 652 373. It is clear that in this instance, given the handling and storage required, only fairly small-sized swimming pools are involved.
For surfaces of larger dimensions recourse may be had to cover devices which also have a drum fixed to one of the transverse ends of the surface that is to be protected. The cover is deployed manually by pulling, being unrolled from the drum, to cover the surface. The weight and the dimensions of the cover require the intervention of a number of individuals in order to fit it correctly. The cover is removed by winding it up around the drum by rotation: the cover is thus removed from the surface by sliding along it. The rotation of the drum in order to remove the cover is performed manually or using an electric motor that is powerful enough to be able to pull the fully deployed cover. It should be emphasized that ease of deployment of the cover, particularly in the case of a swimming pool, is a contributory factor in the safety thereof, because any handling that is awkward discourages its use.
In order to eliminate human intervention, (fully) automatic devices have been proposed; the cover is wound around a motorized drum that can be used for removing it, the drum being fixed to one of the transverse ends of the surface that is to be protected. The cover is deployed by pulling it from its visible end, using automatic pulling means of the rack or chain or hauling cable type, with or without a return pulley, the cover perhaps being guided by guideways arranged at the longitudinal ends of the surface that is to be covered; the cover then slides over the surface, covering it. Likewise, as the cover is removed, it slides over the surface that is to be uncovered as it winds up around the drum. This automatic cover device is illustrated notably in the following documents: U.S. Pat. No. 3,574,979, GB 2 199 741, U.S. 2005/0097834, CA 2 115 113, U.S. 2001/0023506, U.S. Pat. No. 5,930,848, U.S. Pat. No. 4,001,900 and on the website www.aquatop.be.
The two types of cover devices with a drum mentioned hereinabove have the main disadvantage of making the cover slide, which cover is dragged along the surface that is to be protected as it is being deployed and as it is being removed, thus causing premature wear of this cover together with additional work due to the friction thus generated.
To alleviate this disadvantage, there is an alternative type of cover device with a drum, the motorized drum now being mounted on a longitudinal-translation mechanism. This mechanism moves the drum over the surface that is to be covered, allowing the cover to be literally “laid” onto the surface, as it is deployed, by simultaneously unrolling it from the drum while it is being moved longitudinally, then allowing it to be lifted, as it is removed, while simultaneously winding it up onto the drum. The cover therefore slides over the surface neither while it is being deployed nor while it is being removed. The cover device also comprises a system for fixing the cover to a transverse end of the surface that is to be covered such that the translational and rotational movements of the drum cause the cover to be unwound or wound up above the surface that is to be covered.
In this application, the terms “longitudinal”, “transverse” and derivatives thereof refer respectively to the direction of travel of the drum and to the direction of the axis of revolution thereof.
Examples of automatic or semi-automatic devices of this type are disclosed for example in the following documents: WO2005/026473, FR 2 900 951, DE 2 257 231, FR 2 893 651, FR 2 789 425, FR 2 803 769, FR 2 743 502, EP 1 719 858, FR 2 908 402 and BE 2008/0417/0418/0419. Moreover, a completely manual alternative form of the drum mounted for longitudinal translation is illustrated in documents WO2007/036625 and U.S. Pat. No. 4,195,370.
In the mobile-drum cover devices illustrated hereinabove, the longitudinal-translation mechanism can be set in motion either entirely by hand, or semiautomatically or automatically, notably using a gripping member, a cable or a rack in which a pinion meshes.
Racks are advantageous because they do not require return pulleys which are always difficult to conceal and which may easily become jammed. An example of a rack-type longitudinal-translation system is described in applications BE 2008/0417/0418/0419 filed by the same applicant, in which driven cogged wheels mesh with straight racks laid on the ground. However, contact between the drive wheels and the rack is over just a few teeth, and there is still a high risk of slipping of a pinion on the rack with which it meshes, and this slippage would result in the deviation of the travel of the drum.
There therefore still remains a need regarding an automatable system for covering a surface, equipped with a mechanism for the longitudinal translational movement of the drum with a substantial reduction in the risk of slippage between a pinion and the rack with which it meshes, and therefore deviating the travel of the drum.